For many years numerous surgical procedures have been performed to stabilize and align (or re-align) parts of the skeletal structure of mammals. These surgeries include the alignment of existing joints as well as the fusion or attachment of one part of a bone to another part of a bone that have been separated surgically or otherwise. A surgical osteotomy for example is a procedure where a bone is cut to change the alignment (lengthen, shorten or otherwise change).
Bunion and/or hallux valgus surgeries are examples of applications for some embodiments of this invention wherein a bone is surgically cut or separated into two pieces or portions (osteotomy), and then surgically fixed back together in a more desired multi-planar and/or rotational alignment and stabilization. “Hallux” is used as another name for a person's big toe, and generally includes two bones or “phalanges” and valgus generally refers to a deformation of a bone or joint. The term “hallux valgus” typically refers to a deviation of the big or great toe toward the inside portion or fibular border of the foot.
An example of this type of surgical procedure relates to bunion surgery, which may also be referred to as a bunionectomy or a surgical procedure to correct or relieve a bunion. A bunion is a distortion or enlargement of a joint in the big toe which causes the big toe to curve outwardly toward the other toes in the foot. The metatarsal bone protrudes medially and can rotate externally (see FIG. 1).
In a typical foot the first intermetatarsal angle is in the five to ten degree range (generally under fifteen degrees), whereas in a foot with metatarsus primus varus, the first intermetatarsal angle may be greater than fifteen degrees and can increase to twenty degrees or more. The “first” intermetatarsal angle is the angle between the first and second metatarsal bones. A metatarsus primus varus is a condition in which the first metatarsal bone has an increased angle away from the second metatarsal bone and some rotational distortion.
Some estimate there are approximately two-hundred thousand to four-hundred thousand bunion or Hallux Valgus (HV) surgical procedures performed every year. Metatarsus primus generally occurs along with bunion and hallux valgus.
The difficulties with some of the prior art surgical procedures are multiple and many modifications of the basic procedure have been proposed and explored. However despite the years of attempts to modify the bunionectomy, there is still a relatively high rate of patient dissatisfaction with bunion and hallux valgus types of surgeries.
In the bunion surgery example the deformity most often addressed by the surgical procedure is the increase in the angle between the first and second metatarsals, an example of which is illustrated in FIG. 1 (angle 93). The view of the deformity shown in FIG. 1 only shows one plane of deformation whereas in most bunion conditions the patient has deformity in multiple planes and some further include rotational deformity (angle 94, FIG. 1). In the prior art these deformity angles may be referred to as the first intermetatarsal angle (“IMA”) and the second intermetatarsal angle, with the first intermetatarsal angle being the angle between the first and the second metatarsal bones.
It is believed that in many bunion surgeries the failure to recognize and/or solve the frontal plan rotation deformation for example, results in less than desirable surgical results. The prospects for a successful surgical procedure are further limited by the difficulties associated with the imprecise nature of being able to more precisely view and align the two part/portions of the bones or portions/parts/pieces of bones being fixed together (or the joint being re-aligned).
Only a few of the existing surgical procedures or systems address both the translational and rotational deformity issues. One of the most common surgical procedures used to address the translational and rotational deformity issues is referred to as a Lapidus Bunionectomy, in which the first metatarsal is fixed to the medial cunefiform. Unfortunately the Lapidus Bunionectomy has historically had a four to six week non-weight bearing postoperative healing period.
Despite the longstanding and recognized need for an improved system to address the various deformities and/or issues typically associated with skeletal or bone misalignment and/or deformity in mammals, there is still a need for an improved system.
Aspects of this invention such as the cannulated aspect of the implant device have an advantage of providing the surgeon an additional alignment tool for use during the surgery in combination with what is referred to as a wire or “K-wire”. The term K-wire is used broadly in the surgical field to refer to a wire or pin that may have numerous deviations (sharpened portions, threaded portions, various or varying thicknesses, etc). K-wires were originally referred to as Kirschner wires because Martin Kirschner was originally credited with the introduction of the wires into surgery in the early 1900's.
In surgeries, K-wires may be conveniently used for temporary or permanent fixation. In some applications K-wires may first be inserted into one part or portion of the bone or joint, and then the intramedullary and extramedullary portions of one embodiment of the invention can be slide over the K-wire to achieve more consistent improved alignment of the device. This will lead to more consistent desired (or improved) alignment of the joint and/or fusion.
It is therefore an object of some embodiments of this invention to provide an improved stabilization and/or alignment system which may be used to address bone and joint alignment issues generally, and which may include foot related bunion and unwanted metatarsal deformations.
It is a further object of this invention to provide such system which provides an improved alignment tool during the surgical procedure, such as by providing a cannulated intramedullary portion that is disposed to be inserted into a bone over the wire or k-wire as a guide. It is a further object to provide such a system wherein the extramedullary portion is also cannulated.
Other objects, features, and advantages of this invention will appear from the specification, claims, and accompanying drawings which form a part hereof. In carrying out the objects of this invention, it is to be understood that its essential features are susceptible to change in design and structural arrangement, with only one practical and preferred embodiment being illustrated in the accompanying drawings, as required.